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| 2014年鲁甸MS6.5地震形变高频信息异常与前兆机理浅析 | |
| 引用本文： | 龚丽文,刘琦,张治广,武善艺,陈丽娟.2014年鲁甸MS6.5地震形变高频信息异常与前兆机理浅析[J].地震,2019,39(1):101-113. |
| 作者姓名： | 龚丽文 刘琦 张治广 武善艺 陈丽娟 |
| 作者单位： | 1.重庆市地震局, 重庆 401147; 2.中国地震局地震预测研究所, 北京 100036; 3.新疆维吾尔族自治区地震局, 新疆 乌鲁木齐 830011; 4.甘肃省地震局, 甘肃 兰州 730000 |
| 基金项目： | 2016年度地震监测预报专项项目(2016030509); 2017年度震情跟踪课题(2017010231)共同资助 |
| 摘 要： | 地震前兆异常的识别和提取一直是地震预报研究的重要任务, 也是地震预报事业发展的瓶颈。 结合鲁甸地震的研究成果, 利用S变换和超限率等方法, 提取定点形变高频异常, 总结鲁甸地震前兆高频异常形态特征, 分析异常台站空间分布规律, 剖析高频异常形成的前兆机理。 研究发现, 高频异常主要表现为信号周期在数分钟至数小时的信号成分, 频带较宽, 丛集性好, 与曲线的突跳、 毛刺或阶跃对应较好, 震前4~5 d开始出现, 震后2~3 d衰减消失; 其台站分布较分散, 主要沿NW—SE方向分布, 与区域应力场方向和发震断层走向趋于一致, 且均分布在构造块体边界; 可能是对不同速率的构造块体在震前发生的滑移和瞬间错动的记录, 它的形成与台站附近地壳介质的稳定性有关。 |
| 关 键 词： | S变换 超限率分析 高频异常 前兆机理 2014年鲁甸MS6.5地震 |
| 收稿时间： | 2017-07-26 |
High-frequency Information Anormalies of Deformation and Its Precursory Mechanism before the Ludian MS6.5 Earthquake |
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| GONG Li-wen,LIU Qi,ZHANG Zhi-guang,WU Shan-yi,CHEN Li-juan.High-frequency Information Anormalies of Deformation and Its Precursory Mechanism before the Ludian MS6.5 Earthquake[J].Earthquake,2019,39(1):101-113. | |
| Authors: | GONG Li-wen LIU Qi ZHANG Zhi-guang WU Shan-yi CHEN Li-juan |
| Institution: | 1.Earthquake Administration of Chongqing Municipality, Chongqing 401147, China; 2.Institute of Earthquake Science, CEA, Beijing 100036, China; 3. Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China; 4.Earthquake Administration of Gansu Province, Gansu Xining 730000, China |
| Abstract: | The recognition and extraction of seismic precursory anomalies are important tasks for earthquake prediction research, and they are also the bottleneck of development of earthquake prediction. In this paper, combined with the results of Ludian earthquake research, its high-frequency abnormalities of the fixed-point deformation by the methods of S-transform and overrun rate are extracted. Then, the abnormal morphological characteristics are summarized and its regularities of distribution are analyzed. Finally, the precursory mechanism of high-frequency abnormal are dissected. According to the analysis, the signal components of high-frequency anomalies are mainly composed of several minutes to several hours of signal with a wide frequency band and a good cluster. It begun 4~5 days before the earthquake and disappeared in a week, which was accompanied by the kick and step abnormalities of the curve. The distribution of anomalies was along with the NW-SE tectonic block boundary, which was consistent with the direction of regional stress and the seismogenic fault trend. It could be a record of slip and instantaneous rupture between different rates of tectonic block, and its formation also related to the stability of the crustal medium near the station. |
| Keywords: | Ludian MS6 5 earthquake High-frequency information anomalies S transformation Overrun Rate Analysis(ORA) Precursor mechanism |
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